Liquid cooling system for use on snowmobiles

ABSTRACT

A cooling system for the engine coolant of a liquid cooled snowmobile engine. The cooling system is provided as a substitute for or a supplement to a conventional radiator normally used with internal combustion, liquid cooled engines. The cooling system comprises elongated tubes mounted adjacent the tunnel used for the snowmobile drive track whereby snow will drop directly onto the tubes to remove heat from the coolant at a relatively high rate as the snow is changed into a liquid.

Duclo Sept. 17, 1974 LIQUID COOLING SYSTEM FOR USE ON SNOWMOBILES [75]Inventor: Marley J. Duclo, Brooten, Minn.

[73] Assignee: HVP, Inc., Crosby, Minn.

[22] Filed: Dec. 15, 1972 [21] Appl. No.: 315,278

[52] US. Cl 180/5 R, 123/4101, 180/68 [51] Int. Cl B62m 27/02, 862k 11/04 [58] Field of Search 180/5 R, 68. 54 A, 54 R [56] References CitedUNITED STATES PATENTS 657,684 9/1900 Vorreiter 180/54 A 2,581,072 l/l952Brezek 180/68 R 3,404,745 10/1968 Smieja 180/5 R 3,485,312 12/1969Swenson 180/5 R Primary Examiner-Robert S. Ward, Jr. AssistantExaminer-Reinhard J. Eisenzopf Attorney, Agent, or Firm-Dugger. Johnson& Westman [57] ABSTRACT A cooling system for the engine coolant of aliquid cooled snowmobile engine. The cooling system is provided as asubstitute for or a supplement to a conven tional radiator normally usedwith internal combustion, liquid cooled engines. The cooling systemcomprises elongated tubes mounted adjacent the tunnel used for thesnowmobile drive track whereby snow will drop directly onto the tubes toremove heat from the coolant at a relatively high rate as the snow ischanged into a liquid.

7 Claims, 5 Drawing Figures LIQUID COOLING SYSTEM FOR USE ON SNOWMOBILESBACKGROUND OF THE INVENTION 1. Field of the Invention The presentinvention relates to cooling systems for snowmobiles having liquidcooled engines.

2. Prior Art The usual snowmobile construction is well known, and hasgained wide popularity in the areas that have snow. The advent of liquidcooled engines for snowmobiles, which have several advantages inoperation, as opposed to the more usual air cooled engine, has givenrise to a problem on how to adequately cool the engine without taking upa great deal of space, and without providing power consuming fans.Conventional radiators for cooling internal combustion engines of courseare known, and there have been units that have used auxiliary coolingcoils or radiators for automobiles. For example, U.S. Pat. No.s2,503,411 and 2,581,072 relate to the general concept of auxiliarycooling radiators that are spaced away from the engine itself.

However, even this involves the use of a supplementary radiator as wellas the conventional radiator and these require a substantial amount ofspace.

On the other hand, in the operation of snowmobiles, the machine itselfis in an enviroment which includes a frozen solid, namely snow, thatwill provide cooling if the material is utilized. Also, most snowmobilesuse an endless drive track or belt and this belt is usually enclosedwithin a housing or tunnel. The belt carries snow with it as it moves,and the snow carried into the tunnel forms a cooling medium. The usualtunnel and drive belt construction is well known, and typicalconstructions are shown in U.S. Pat. No. 3,485,312 and U.S. Pat. No.3,701,394.

SUMMARY OF THE INVENTION The present invention relates to a coolingsystem for use in snow vehicles which have liquid cooled engines. Thecooling system comprises elongated tubular members for carrying theliquid coolant from the engine into position where the tubes will becontacted by snow as the vehicle moves. In the form shown, the tubes aremounted on the tunnel for the drive track of a snowmobile, and arepositioned so that the snow thrown up by the drive track will contact atleast a portion of the tubes to provide for a heat exchange. The meltingof the solid snow requires a substantial amount of heat which is removedfrom the coolant.

The unit can be used in combination with a conventional radiator, orwithout a radiator. In addition, the mounting in the tunnel will help toprovide for air circulation because the belt carries air with it as itmoves inside the tunnel.

' In the form disclosed, the unit is made with a surge tank but withoutany conventional radiator. The engine has a water pump on it, to providefor circulation of the coolant through the tubes. The tubes as shownhave sections mounted on the inside of the vertical walls of the tunnel,and other sections on the outside of the tunnel. A cross over pipe tothe rear of the track carries coolant in a closed path from one side ofthe tunnel to the other and then other tube sections carry coolant backto the engine. The tubes can include fins for catching the snow, andalso for better heat exchange.

The elongated tubes result in efficient heat exchange between thecoolant and the snow contacting the tubes. The snowmobile does not haveto be made to accommodate a radiator, nor does it have to have provisionfor air flow across the radiator in the engine compartment. This makesthe styling of the snowmobile easier, and also insures that the heatedair coming from the radiator is not a problem in snowmobile operation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic side elevationalview of a typical snowmobile showing a drive track and the location ofthe cooling tubes made according to the present invention;

FIG. 2 is a sectional view taken as on line 22 in FIG. 1;

FIG. 3 is a sectional view in plan showing the positioning of thecoolant tubes on the sides of the tunnel, and also showing fragmentarilythe snowmobile engine;

FIG. 4 is a side view of a typical coolant tube used with the presentinvention; and

FIG. 5 is a sectional view taken as on line 55 in FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIGS. 1 and3, a snowmobile indicated generally at 10 is provided with a liquidcooled internal combustion engine 11, as shown a three cylinder engine,which has the usual internal cooling passageways around the cylinders ina conventional manner. The internal passageways of the engine are notspecifically shown because they are well known and can be made in anydesirable configuration. Suitable drive means are provided from thecrankshaft of the engine to drive sprockets 12 mounted on a suitablecross shaft 13 mounted on a support frame tunnel 14 to the rear of theengine. A pair of idler sprockets 15 are also provided on a shaft 16rotatably mounted at the rear end of the snowmobile in the usual manner.The drive from the engine to the shaft 13 is shown only schematicallyand is represented by a chain and sprocket 17. The drive can be anydesired type now used with snowmobiles. A suitable torque converter andvariable speed drive coming from the output shaft of the engine isnormally provided.

An endless snowmobile drive track 20 of usual design is mounted over thesprockets l2 and 15. The drive track 20 has provisions for the teeth ofthe sprockets 12 and 15 to engage. Normally these tracks are molded butcan be of any other desired construction. The track has a lower portionor length that engages the snow and an upper portion extending betweenthe top of the sprockets mounting the track. The tunnel 14 is made witha top wall 21, with a first side wall 22, and a second side wall 23attached to the top wall. The tunnel forms a frame member for themachine, and also has support members 24 on opposite sides thereof forthe operators feet. The top wall 21 of the tunnel can support a seat 25.The tunnel is fastened into the other frame members of the snowmobile.

The engine cooling system includes a pump shown schematically at 26 thatis driven by the engine in the usual manner, and the output port of thepump has a pipe 27 leading to the internal passages of the engine. Theoutput side of the engine has a tube 30 leading therefrom, and passingthrough a frame member to a suitable fitting 31 which extends throughthe first wall 22 of the tunnel. This fitting 31 is connected to theinterior of a cooling tube section 32 which is mounted on the inside ofthe first wall 22 of the tunnel adjacent the edge of the track 20. Thiscooling tube section 32 extends rearwardly and downwardly, to a pointabout midway back in the tunnel and is connected to a suitable fittingor pipe 33 which extends through the wall 22 to a second cooling tubesection 34 mounted on the exterior of the wall 22. This second coolingtube section 34 extends rearwardly and upwardly, and is connected to across over tube 35 extending between and through the tunnel walls 22 and23. The cross over tube 35 extends through the wall 23 to the exteriorside thereof and connects to a third cooling tube section 36 thatextends downwardly and forwardly and is connected to a connecting tube37 which is used for connecting the interior of the third tube section36 to the interior of a fourth cooling tube section 38 on the inside ofthe wall 23. The tube 37 extends through the wall 23. The cooling tubesection 38 extends forwardly and upwardly to the forward edge of thetunnel. There, a tubular fitting or connecting tube 40 passes throughthe wall 23 and connects to a return pipe 41 that in turn is connectedto a surge tank 42. The surge tank 42 can have suitable filler openingso that make-up liquid coolant can be added to the surge tank. The surgetank insures that the pump 26 will have an adequate supply of coolant.The pump 26 is shown only schematically, and of course can be positionedin any desired location. Two pumps could be used on the unit, one in thetube or pipe 30 if desired. The tubes or pipes 30, 35, and 41 can beflexible hoses that are attched with suitable hose clamps. Theconnection tubes which pass through walls 22 and 23 and which areconnected between the cooling tubes may be sealed to the cooling tubeswith suitable rings.

When the engine 11 is running, and the pump 26 is driven, the coolantfrom the engine will be pumped through the cooling tubes and connectiontubes in a fluid circuit. A typical cooling tube section is shown inFIG. 4. The tube section 32 is shown for illustrative purposes, and theother tubes are similarily constructed. The connection tubes 31 and 33are at opposite ends of the tube, and the cooling tube has a hollowinterior passageway 43 that extends the length of the cooling tube. Thecooling tube walls are formed so that the cooling tube will fit tightlyagainst the tunnel side walls, and on the side of the cooling tube thatis opposite from the tunnel side walls, the tubes are provided withcooling fins 44, that extend generally upwardly in direction. The fins44 as shown then form small scoops on which falling snow will collectbecause of the upwardly extending direction of the fins 44. The coolantin the interior chamber 43 of course conducts heat rapidly to the wallsof the tube sections because the tube sections are made of metal, andthis heat will cause any snow collecting on the tube sections or fins tomelt. The heat required to melt the snow into a liquid is quite high,and thus the heat is removed from the coolant in the chambers 43 quiterapidly.

The other cooling tube sections are constructed substantially the same,and provide for adequate heat exchange in the tubes. When the snowmobileis being operated, the track of course will be moving and this willgenerate air currents, and also will carry snow upwardly around the backof the track up over to the top portion of the belt. Snow will also bechurned up from the bottom length of the belt, so the tunnel will befilled with snow mixed with air. The quantity of snow thrown up issubstantial. The snow will fall off the sides of the belt and down ontothe fins 44 particularly on the first and fourth cooling tube sections32 and 37. The cooling tube sections 34 and 36 extend the cooling tubesback to the cross over tube without interfering with the back shaft andsprockets of the drive track. The tubes 34 and 36 on the outside of thetunnel are exposed to atmospheric air and provide for heat exchange withthe air. Also snow thrown up by the track will collect on these coolingtube sections and the cooling effects of the melting snow are present atthese tubes as well.

The form of the cooling tubes can be varied of course, and the lengthcan be changed to suit existing conditions. Mounting the tubes on theinterior of the tunnel where they are sure to be contacted by snow fromthe track, or adjacent the track is important because it provides for apositive means for getting a solid frozen material to contact the tubesso that the heat exchange process is aided from the heat requirement forchanging the solid to a liquid.

It should be noted that the flanges on the cooling tubes, as shown inFIG. 5, as upper and, lower flanges can be bolted, riveted or clippeddirectly to the tunnel side walls in order to hold them in position, andalso to insure that the connecting tubes between the cooling tubesremain in position and sealed properly.

The use of cooling tubes in a snow vehicle and the positioning of thecooling tubes adjacent the drive means so that when operating thevehicle the snow churned up by the drive means will contact the tubes,insures adequate cooling.

The liquid coolant used may be any desired type, and of course, in coldweather will include a suitable antifreeze solution, such as an ethyleneglycol and water solution. The cooling system also may be pressurized byuse of a pressure cap on the surge tank opening of the type normallyused on cooling systems in automobile engines.

What is claimed is:

l. A cooling system for a liquid cooled internal combustion enginemounted on a snowmobile, said snowmobile having a belt like drive trackpowered by said engine and engaging the snow for propelling thesnowmobile, said track having a lower portion engaging the snow and anupper portion, at least one tubular coolant carrying member connected tosaid engine, means for circulating coolant through said engine and saidtubular member, and means to position said tubular member adjacent tosaid track whereby snow carried into the air by said track will contactsaid tubular member.

2. The cooling system of claim 1 wherein said snowmobile includes tracksupport means comprising a tunnel member having spaced apart, generallyupright side walls positioned on opposite longitudinal sides of saidtrack, and means to mount said tubular member on said side walls.

3. The cooling system of claim 2 and a plurality of cooling fins mountedon said tubular member in position to catch snow dropping from the edgesof said track.

4. A snowmobile having a power unit and a liquid cooling system for saidpower unit, said snowmobile comprising a main frame member, said powerunit being positioned adjacent to one end of said main frame member, anddrive means for said snowmobile comprising means which contact thesurface over which the snowmobile moves in at least longitudinallyspaced locations with respect to said frame, longitudinally extendingsupport means for supporting the drive means in longitudinally spacedlocations, and an elongated tubular coolant carrying member connected tosaid power unit cooling system and providing circulation of power unitliquid coolant therethrough, and means to mount said coolant carryingmember on said support means and extending in longitudinal directionadjacent to said drive means to provide a path of flow of coolant remotefrom said power unit, and in a location where movement of air isaffected by said drive means.

5. The combination as specified in claim 4 wherein said drive meanscomprises an endless track member mounted to extend longitudinally alongsaid frame.

6. In a cooling system for a snow vehicle having a power unit with aliquid cooling system, said snow vehicle having drive means for engagingthe snow comprising an endless track member, and support means for saidendless track member comprising a downwardly open inverted U shapedtunnel, the improvement comprising tubular coolant carrying meansconnected to said power unit cooling system, and means to mount at leastportions of said tubular coolant carrying means toward the interior ofsaid tunnel adjacent to said endless track member to provide a path offlow of coolant remote from said power unit.

7. A snowmobile having a frame, a power unit for propelling saidsnowmobile, a liquid cooling system for said power unit, and an endlessdrive track member for said snowmobile, a support for said endless drivetrack member comprising a pair of side wall means spaced laterally aparton said frame, and means substantially closing the space between saidside walls above said drive track member with upper portions of saiddrive track member being above the lower edges of said side walls, atubular coolant carrying means connected to the power unit coolingsystem to carry coolant flow remote from said power unit, at leastportions of the tubular coolant carrying means being positioned on saidside walls remote from said power unit and adjacent to said drive trackmember,

1. A cooling system for a liquid cooled internal combustion enginemounted on a snowmobile, said snowmobile having a belt like drive trackpowered by said engine and engaging the snow for propelling thesnowmobile, said track having a lower portion engaging the snow and anupper portion, at least one tubular coolant carrying member connected tosaid engine, means for circulating coolant through said engine and saidtubular member, and means to position said tubular member adjacent tosaid track whereby snow carried into the air by said track will contactsaid tubular member.
 2. The cooling system of claim 1 wherein saidsnowmobile includes track support means comprising a tunnel memberhaving spaced apart, generally upright side walls positioned on oppositelongitudinal sides of said track, and means to mount said tubular memberon said side walls.
 3. The cooling system of claim 2 and a plurality ofcooling fins mounted on said tubular member in position to catch snowdropping from the edges of said track.
 4. A snowmobile having a powerunit and a liquid cooling system for said power unit, said snowmobilecomprising a main frame member, said power unit being positionedadjacent to one end of said main frame member, and drive means for saidsnowmobile comprising means which contact the surface over which thesnowmobile moves in at least longitudinally spaced locations withrespect to said frame, longitudinally extending support means forsupporting the drive means in longitudinally spaced locations, and anelongated tubular coolant carrying member connected to said power unitcooling system and providing circulation of power unit liquid coolanttherethrough, and means to mount said coolant carrying member on saidsupport means and extending in longitudinal direction adjacent to saiddrive means to provide a path of flow of coolant remote from said powerunit, and in a location where movement of air is affected by said drivemeans.
 5. The combination as specified in claim 4 wherein said drivemeans comprises an endless track member mounted to extend longitudinallyalong said frame.
 6. In a cooling system for a snow vehicle having apower unit with a liquid cooling system, said snow vehicle having drivemeans for engaging the snow comprising an endless track member, andsupport means for said endless track member comprising a downwardly openinverted U shaped tunnel, the improvement comprising tubular coolantcarrying means connected to said power unit cooling system, and means tomount at least portions of said tubular coolant carrying means towardthe interior of said tunnel adjacent to said endless track member toprovide a path of flow of coolant remote from said power unit.
 7. Asnowmobile having a frame, a power unit for propelling said Snowmobile,a liquid cooling system for said power unit, and an endless drive trackmember for said snowmobile, a support for said endless drive trackmember comprising a pair of side wall means spaced laterally apart onsaid frame, and means substantially closing the space between said sidewalls above said drive track member with upper portions of said drivetrack member being above the lower edges of said side walls, a tubularcoolant carrying means connected to the power unit cooling system tocarry coolant flow remote from said power unit, at least portions of thetubular coolant carrying means being positioned on said side wallsremote from said power unit and adjacent to said drive track member.